Today, 23 October 2012 is Mahanavami. Mahanavami is celebrated on Ashwin Shukla Paksha Navami, the ninth day of Durga Navratri. During Vasant Navratri, Mahanavami date was April 1, 2012.
Maha Navami is the last day of 9-day festival, Sharad Navaratri. As per Hindu beliefs, Durga puja on Maha Navami is equal to Durga pooja performed on all 9 days of Durga Navaratri.
Goddess Siddhidatri puja is performed on Mahanavami day.
On Mahanavami day, in South Indian states especially in Kerala, Ayudha Pooja is performed. Tools, operators, instruments and books are worshipped. The next day of Mahanavami is observed as Vijaya Dashami.
In some rural places, Janthu bali (animal sacrifices) are performed on Mahanavami day. It is to be noted that Hindu culture and society is against animal sacrifices.